A/C compressor load rating for conductor sizing

[joecalvin]

Guys, we recently received an updated schedule for A/C requirements from Lennox. The MCA for a 4 ton unit is now 33a and it is calling for a 50a 2P breaker for the circuit. Can we run #8 for this circuit based on the MCA or do we need to run #6 to match the breaker rating?

Let me know.

Thanks
Joe

 

[texie]

Yes, the conductors are sized to the MCA, not the breaker. BTY, if using pipe and wire as opposed to NM cable, you could still use #10 conductors as long as the equipment is rated for 75 degree terminations (likely are).

 

[infinity]

Guys, we recently received an updated schedule for A/C requirements from Lennox. The MCA for a 4 ton unit is now 33a and it is calling for a 50a 2P breaker for the circuit. Can we run #8 for this circuit based on the MCA or do we need to run #6 to match the breaker rating?

Let me know.

Thanks
Joe

As texie stated #10 conductors may be code compliant with the 50 amp OCPD.

 

[tom baker]

This issue trips up many electricians….

 

[acin]

Check out mikes free video AC circuit sizing

 

[joecalvin]

Thanks guys, I appreciate everyone's input on this.

Have a great weekend all.

Joe